Commit Graph
78 Commits
Author SHA1 Message Date
Johnathan Corgan 6991a152e6 Merge maint into master (outbound admission gate + mesh-size parent skip)
Brings two structural fixes landed on maint:
- compute_mesh_size: explicit parent skip in the children loop, so the
  disjoint-subtree invariant no longer depends on peer_declaration cache
  freshness.
- max_peers: outbound connection-initiation gated on the cap (auto-reconnect
  retries, Nostr-mediated discovery established adoption, and both sides
  of the NAT-traversal punch sequence). Inbound msg1 admission gate
  unchanged.
2026-05-26 17:31:47 +00:00
Johnathan Corgan d4687e5d30 node: gate outbound connection initiation on max_peers
node.limits.max_peers was honored only on inbound msg1 admission
(handshake.rs handle_msg1 returns PeerLimitExceeded when peers.len
is at the cap). Four outbound initiation paths proceeded unconditionally
at capacity: auto-reconnect retries (process_pending_retries),
Nostr-mediated discovery's BootstrapEvent::Established adoption
(poll_nostr_discovery), NAT-traversal punch initiation (the outgoing
side of the offer/answer/punch sequence in the Nostr discovery
runtime), and NAT-traversal punch response (the incoming side of the
same sequence). A saturated node burned CPU, UDP probes, STUN
observations, and Nostr relay traffic on connections that the inbound
gate would reject the moment they reached msg1.

Introduce Node::outbound_admission_check (peers.len < max_peers, or
true when max_peers == 0 as the no-cap sentinel) and gate the four
paths. The discovery runtime lives in a separate task and does not
hold a Node reference; bridge via an Arc<AtomicBool> the runtime
reads and Node refreshes once per tick from outbound_admission_check.
The atomic granularity is intentionally loose: one-tick lag is
acceptable because the inbound msg1 gate continues to be the
authoritative cap, and in-flight handshakes started below the cap
are allowed to complete.

Inbound gate at handshake.rs is unchanged.
2026-05-26 17:08:56 +00:00
Johnathan Corgan df43ac79b9 node: skip parent explicitly in compute_mesh_size children loop
The mesh-size estimator's children loop relied on the cached
peer_declaration(parent_id).parent_id() != my_addr check to exclude
the parent. That cached view briefly disagrees with our own latest
my_declaration().parent_id() during the window between a local
parent-switch and the new parent's next inbound TreeAnnounce: the
peer-declaration cache still names us as the parent's parent, so the
parent is iterated as if it were a child and its (typically dominant)
bloom cardinality is added a second time. Symptom: estimated mesh size
displayed in fipsctl show status and fipstop nearly-but-not-exactly
doubles during tree rebalancing.

Make the invariant structural with an explicit peer_addr == parent_id
skip at the head of the children loop. Per-peer 500 ms rate-limiter
and overall recompute cadence are unchanged.

Adds a regression test that constructs the stale-peer-declaration
scenario directly and asserts the parent is not double-counted.
2026-05-26 16:55:11 +00:00
Johnathan Corgan 18297283ad Merge maint into master (rx_loop tick-arm connect-on-send fix) 2026-05-25 05:02:01 +00:00
Johnathan Corgan 4d5380604a node: don't drive connect-on-send from the rx_loop tick path
The tick body's per-peer check_* loops (heartbeats, bloom
announces, MMP reports, tree announces) called transport.send
for every active peer, which on TCP/Tor fell through to a 5 s
connect-on-send wait for any peer whose pool entry was not yet
established. That wedged the entire tick body for the full
connect_timeout_ms per unreachable peer; under post-restart
convergence on a high-peer mesh, this cascaded into multi-
second tick stalls. On master, the same mechanism also starved
the per-tick control-snapshot republish and pushed fipsctl
queries onto an mpsc fallback that was itself queued behind
the wedged rx_loop, producing the 5-second fipsctl head-of-line
pattern operators observed on loaded nodes.

Gate send_encrypted_link_message_with_ce on
transport.connection_state before the send: proceed only when
Connected; on None, kick off a non-blocking background connect
(idempotent — TransportHandle::connect dedupes against the
connecting pool and spawns the timeout-bounded TcpStream::connect
inside its own tokio task) and fail this send fast with a
clear "transport connection not ready" error. A subsequent
tick retries once the pool has an entry. The reconnect
lifecycle (check_link_heartbeats, process_pending_retries,
poll_pending_connects) is unchanged. The connect-on-send
branch in transport.send_async itself remains in place for
code paths that legitimately need synchronous connect (e.g.,
explicit operator-driven fipsctl connect).
2026-05-25 04:50:30 +00:00
Martti MalmiandJohnathan Corgan 0a5c367edc data-plane perf overhaul: off-task encrypt + decrypt, GSO, connected UDP
Moves both AEAD layers (ChaCha20-Poly1305, one round per layer per
packet) plus the sendmsg syscall off the rx_loop task onto a per-shard
worker pool, adds per-peer connect(2)-ed UDP with SO_REUSEPORT, and
uses Linux UDP GSO (sendmsg+UDP_SEGMENT — kernel splits one super-skb
into N on-the-wire datagrams in a single TX-stack walk) when packets
in a batch are uniform-size. Same kernel primitive WireGuard's
in-kernel module and BoringTun use to hit 2.5–3.2 Gbps single-stream.

Single TCP stream on a 5-node docker-bridge mesh, 5 x 15 s x P=1:

  A→D:  1379 → 2708 Mbps  (1.96x, RTT +0.12 ms)
  A→E:  1394 → 2663 Mbps  (1.91x, RTT +0.11 ms)
  E→A:  1406 → 2624 Mbps  (1.87x, RTT +0.19 ms)

Static-peer pairs only — every CoV under 3%, 0 outliers, 0% ICMP
loss. The ~+100 µs RTT is the worker queue handoff cost; AEAD +
sendmmsg now run on a separate core in exchange.

What lands:

- src/node/encrypt_worker.rs: std::thread + crossbeam_channel
  workers; hash-by-destination dispatch pins a TCP flow to one
  worker so wire ordering is preserved; per-worker sendmmsg(2)
  batching up to 32; Linux uses sendmsg(2)+UDP_SEGMENT when
  packets in a group are uniform-size.

- src/node/decrypt_worker.rs: receive-side mirror. Each shard owns
  its session's recv cipher + replay window in a thread-local
  HashMap (no shared RwLock/Mutex). Sessions are handed off at
  promote_connection and re-registered on K-bit flip / rekey
  cutover.

- src/node/handlers/session.rs try_send_session_data_pipelined:
  FSP+FMP both seal in-place in the worker on one wire-buffer
  alloc; no intermediate inner_plaintext / fsp_payload Vecs.

- src/transport/udp/connected_peer.rs + peer_drain.rs: per-peer
  connect(2)-ed UDP socket with SO_REUSEPORT (set on the listen
  socket too — without that, EADDRINUSE on activation and every
  packet falls back to the wildcard path); the worker sends with
  msg_name=NULL and the kernel uses its cached 5-tuple. Tick-
  driven activation in handlers/connected_udp.rs, idempotent.

- src/transport/udp/mod.rs: mem::replace the recvmmsg backing buffer
  instead of buf.to_vec() per packet — single pointer swap, no
  MTU-sized memcpy.

- src/protocol/link.rs SessionDatagramRef: zero-copy borrowed view
  used by handle_session_datagram for the bulk local-delivery
  path; handle_session_payload takes the borrowed payload
  directly (no payload[35..].to_vec()).

- src/transport/mod.rs TransportAddr::from_socket_addr: collapses
  the two-alloc from_string(addr.to_string()) pattern to one.

- src/node/handlers/rx_loop.rs: decrypt-fallback drain promoted
  ahead of packet_rx in the select! (TCP ACK starvation fix);
  interleaved fallback drain every 32 packets inside the rx burst
  loop.

- noise::Session: send_cipher_clone / recv_cipher_clone /
  recv_replay_snapshot_owned / take_send_counter / accept_replay
  so off-task workers can hold a cloned cipher + reserved counter
  while the dispatcher keeps replay/counter sequencing serial.
  CipherState::cipher_clone returns a refcount-bumped LessSafeKey.
  AsyncUdpSocket: AsRawFd so workers issue raw sendmmsg / sendmsg
  without going through the tokio reactor.

- Worker pool sizing: both default to num_cpus, overridable via
  FIPS_ENCRYPT_WORKERS=N / FIPS_DECRYPT_WORKERS=N. Per-peer
  connected UDP can be disabled via FIPS_CONNECTED_UDP=0.

- src/perf_profile.rs: optional per-stage timing reporter under
  FIPS_PERF=1 (or FIPS_PIPELINE_TRACE=1). Off by default; zero
  overhead when disabled.

- All cfg(unix)-gated. Windows continues on the existing tokio-
  based send/recv.

Decrypt worker session lifecycle:

- Node::unregister_decrypt_worker_session mirrors the existing
  register helper. Wired at the two natural sites that already
  iterate peers_by_index: the rekey drain-completion block in
  handlers/rekey.rs (drops the worker entry for the old our_index
  once the drain window has expired and the cache_key is
  unreachable to any in-flight OLD-K packet), and remove_active_peer
  in handlers/dispatch.rs (drops the worker entry for each of the
  four index slots: current, rekey, pending, previous). Only
  our_index is normally registered; unregister_session is fire-
  and-forget for missing entries, so calling unconditionally on
  all four slots is correct and bounds the cleanup without per-
  slot accounting. Without these callers the per-worker sessions
  HashMap and the Node's decrypt_registered_sessions set would
  grow monotonically per rekey on long-lived peers.

Testing:

- testing/static/scripts/bench-multirun.sh: multi-run iperf3 +
  ping bench. N reruns (default 5), median / min / max / CoV % /
  per-run outlier flag, avg ping RTT, ICMP loss %, TCP retransmit
  total. Plain client→dest labels + topology header. Pre-bench
  peer-convergence check (FIPS_BENCH_CONVERGE_SECS, default 15);
  per-path route verification via stats.bytes_sent deltas — fails
  fast if traffic exits via a non-static-peer link.

- testing/static/docker-compose.yml: passes FIPS_ENCRYPT_WORKERS /
  FIPS_DECRYPT_WORKERS / FIPS_PERF through to containers for A/B
  benchmarking without rebuilds.

- testing/static/scripts/iperf-test.sh: same plain client→dest
  labels + topology header (was multihop/direct/N hop, which
  conflated topology distance with on-wire path).

- .config/nextest.toml: synthetic UDP node tests serialized
  through a max-threads=1 test group. Localhost handshakes drop
  on shared CI runners under parallel load; one-at-a-time keeps
  assertions reliable.

- src/node/tests/spanning_tree.rs: repair_missing_edge_handshakes
  — retries up to 5 times for synthetic edges whose msg1 was
  dropped, with a drain after each edge retry instead of after
  each attempt's full burst.

- src/node/decrypt_worker.rs::tests: two unit tests asserting
  WorkerMsg::UnregisterSession removes the worker-thread session
  HashMap entry (handle_msg_unregister_session_removes_entry) and
  is a no-op for never-seen cache_keys
  (handle_msg_unregister_session_idempotent_on_unknown_key), which
  is the safety invariant the unconditional unregister calls at
  the four index slots in remove_active_peer rely on.

- src/node/encrypt_worker.rs::unix_tests
  pipelined_send_wire_layout_roundtrips_canonical_decoders: mirrors
  the encoder geometry of try_send_session_data_pipelined (no
  coords, the common established-session path), runs the worker's
  real seal + send via flush_direct_batch_sync, and decodes the
  resulting wire packet using only canonical receive-side decoders
  (EncryptedHeader::parse, SessionDatagramRef::decode, FSP header
  parse, noise::open). Any divergence between the hand-rolled
  encoder offsets (fsp_aad_offset, fsp_plaintext_offset) and the
  decoders fails at one of the parse / open / decode steps before
  the inner-plaintext assertion fires. Complements the existing
  fsp_preseal_runs_before_outer_fmp_seal test which covers the
  seal-ordering invariant with synthetic headers but does not
  exercise the wire-layout invariant.

CHANGELOG.md [Unreleased] # Changed entry added describing the
worker-pool threading model, hash-by-destination dispatch,
sendmmsg/UDP_GSO, per-peer connected UDP, the operator-facing env
vars, and the bench numbers above.

Cherry-picks from mmalmi/master (paths translated from
crates/fips-core/src/ to src/): 9b7c723, 0deb5cb, 13f7339, e036c0e,
3740a68, 3792f83, 8510193, 4910b07, e53f545, e4e2896, 5fe4af5,
1d01ada, 8c37008, e12469e, 6eb2860.

Co-authored-by: Johnathan Corgan <johnathan@corganlabs.com>
2026-05-19 20:53:31 +00:00
Johnathan Corgan 4f3d2f8471 rekey: apply symmetric jitter to desynchronize dual-initiation
Add a per-session signed jitter offset (uniform [-15, +15] seconds)
to the rekey timer triggers in check_rekey (FMP) and check_session_rekey
(FSP). The configured `node.rekey.after_secs` becomes the nominal
interval rather than a floor; mean is preserved. Desynchronizes
both endpoints in symmetric-start meshes so the dual-initiation
race stops occurring rather than being resolved after the fact by
the smaller-NodeAddr tie-breaker.

Per-session storage means each rekey cutover reconstructs the
session and redraws the jitter naturally — successive cycles get
independent offsets, preventing drift back into sync.
2026-05-14 16:32:07 +00:00
Johnathan Corgan a62a0a6cf4 nostr: suppress retraversal of cross-FMP-version peers
Open-discovery NAT traversal succeeds at the UDP layer regardless
of what FMP-protocol version the peer speaks. When the daemon
discovers a peer running a different FMP version (e.g. a v0/v1 mix
during a mid-rollout window, or a misconfigured peer in the same
advert namespace), the punch sequence completes, the socket is
adopted via `Node::adopt_established_traversal`, and we initiate
an FMP handshake. The peer drops our msg1 at its own version-gate
and we drop their msg1/msg2 at `Unknown FMP version, dropping`.
Neither side advances the handshake.

Today the bootstrap transport sits idle until the 31s stale-
handshake timeout, drops, and the open-discovery sweep ~30s later
fires the full STUN+offer+answer+punch sequence again — every
minute, indefinitely, against peers the handshake literally cannot
complete with.

Add a `Node::bootstrap_transport_npubs` map populated alongside
`bootstrap_transports` at adopt time. The rx loop reverse-maps the
transport_id → npub on version-mismatch and bumps the discovery
layer's `failure_state` to a long structural cooldown via the new
`NostrDiscovery::record_protocol_mismatch` API. The next sweep
skips the npub for `protocol_mismatch_cooldown_secs` (default
86400 = 24h, separate from the 30-min transient-failure
`extended_cooldown_secs`).

One-shot WARN per fresh observation. Repeat mismatches inside the
cooldown window are silent (the failure_state method returns false
when an existing comparable cooldown is already in place). The
handshake/transport teardown chain is unchanged — the fix is
specifically about preventing the *next* sweep cycle from
re-traversing.

Cleared on `cleanup_bootstrap_transport_if_unused` and on the
adopt-failure rollback path so completed handshakes don't leave
stale entries behind.

Four new unit tests in `failure_state.rs` cover fresh-entry
signaling, repeat-suppression inside the window, streak-pin
behavior for `show_peers` rendering, and post-cooldown re-arming.
2026-05-06 15:02:26 +00:00
Johnathan Corgan bcc9c525d3 nostr: per-peer NAT-traversal failure suppression and clock-skew handling
Public-test daemons with populous open-discovery caches generate
sustained NAT-traversal-failure WARN volume (~140/hour, ~3500/day)
against cache-learned peers that have gone offline — their adverts
are absent from major Nostr relays but cached entries persist until
their advertised `valid_until` expires. The daemon kept publishing
offers indefinitely under exponential backoff with no per-peer
suppression, drowning operator signal and hammering relays. A
parallel concern: the strict freshness check at signal.rs silently
rejected offers under modest clock skew (now_ms() anchors to
SystemTime once at startup, so post-startup NTP step adjustments
don't propagate on long-uptime daemons), indistinguishable from
"peer is offline."

Six independent improvements layered on the existing retry logic.

Per-npub WARN log rate-limit
----------------------------
New `FailureState` struct on `NostrDiscovery` records per-npub
`last_warn_at_ms`. Subsequent failures inside `warn_log_interval_secs`
(default 5 min) emit DEBUG instead of WARN. Each WARN now also
carries `consecutive_failures` and remaining `cooldown_secs` so
operators can read the trajectory without grepping multiple lines.

Per-npub consecutive-failure counter + extended cooldown
--------------------------------------------------------
After `failure_streak_threshold` (default 5) consecutive failures
against a peer, the next `extended_cooldown_secs` (default 1800)
of attempts are suppressed by pushing
`retry_pending[npub].retry_after_ms` past the cooldown wall. The
open-discovery sweep also consults `cooldown_until` and increments
a new `skipped_cooldown` counter so a peer whose `retry_pending`
was cleared by max_retries doesn't get re-enqueued during the
cooldown window. Caps offer-publish rate per dead peer regardless
of how often the sweep tries to re-enqueue.

Stale-advert eviction on streak-threshold transition
----------------------------------------------------
On the threshold-crossing transition (one-shot, not every
subsequent failure), `tokio::spawn` an active re-fetch of the
peer's Kind 37195 advert from `advert_relays`. Three outcomes:
- absent on relays → cache evicted; sweep won't re-enqueue
  (peer is genuinely gone).
- newer `created_at` → cache refreshed + streak reset
  (peer republished; allowed to retry immediately).
- same → cache untouched; cooldown stands.

Cost: ~one fetch per dead peer per 30-min cooldown cycle, vs
hundreds of offer publishes/hour today.

Clock-skew tolerance on freshness check
---------------------------------------
`signal.rs` `validate_offer_freshness` and
`validate_traversal_answer_for_offer` now allow ±60s grace beyond
strict TTL. Both return a new `FreshnessOutcome` enum so callers
can DEBUG-log when an offer/answer was only accepted via the grace
window. `FRESHNESS_SKEW_TOLERANCE_MS` is hard-coded — loosening
this past minutes erodes the freshness/replay security boundary
and operators tend to tune in the wrong direction.

NTP-style skew estimate (offer_received_at echo)
------------------------------------------------
Added optional `offerReceivedAt: Option<u64>` field to
`TraversalAnswer` payload. Responder fills it with `now_ms()` at
offer-receipt time. Initiator computes the standard NTP offset
formula `((T2-T1) + (T3-T4)) / 2` against the round-trip and
DEBUG-logs when `|skew| ≥ 30s`. Skew is also stashed in
`FailureState` and surfaced in `show_peers`. Non-breaking — older
responders that don't fill the field still produce valid answers,
and `estimate_clock_skew` returns `None`.

Per-peer state in `show_peers` JSON
-----------------------------------
Each peer entry in `show_peers` now carries:

  "nostr_traversal": {
    "consecutive_failures": <u32>,
    "in_cooldown": <bool>,
    "cooldown_until_ms": <u64 | null>,
    "last_observed_skew_ms": <i64 | null>
  }

Always emitted (schema-stable); values populated when discovery is
enabled and the npub has a recorded entry. Required a new public
`Node::nostr_discovery_handle()` accessor and refactored
`FailureState`'s internal Mutex from `tokio::sync` to `std::sync`
(operations never hold across await), which lets the synchronous
`show_peers` handler call `snapshot()` directly without the
dispatcher becoming async.

New config knobs (under `node.discovery.nostr`)
-----------------------------------------------
  failure_streak_threshold: 5
  extended_cooldown_secs: 1800
  warn_log_interval_secs: 300
  failure_state_max_entries: 4096

Tests
-----
12 new unit tests:
- 5 in `tests.rs` covering freshness strict / tolerated / rejected
  outcomes, NTP skew estimation, and the backward-compat None case
  when the responder didn't fill `offer_received_at`.
- 7 in `failure_state.rs` covering streak/warn-rate-limit state
  transitions, cooldown active vs expired semantics,
  success-resets-streak, observed-skew records, and size-cap
  eviction by oldest `last_failure_at`.

CHANGELOG entries added under `[Unreleased]` Fixed.
2026-05-04 12:39:51 +00:00
Johnathan Corgan 037a965a93 Mirror reactive MtuExceeded into path_mtu_lookup
When a transit forwarder drops an oversized data packet and reports
the bottleneck back via MtuExceeded, the receive-side handler
already updates per-session MmpSessionState::path_mtu (used by PTB
synthesis to feed kernel TCP). It did not, however, update
path_mtu_lookup — the per-destination map the TUN reader/writer
consult at TCP MSS clamp time. So forward-path-asymmetry flows kept
clamping at the discovery reverse-path value (too generous for the
actual forward-path budget) on every subsequent SYN.

Add the missing write at the same point apply_notification runs.
Keep the tighter of existing-or-new — the clamp must never loosen.
Same write-shape as seed_path_mtu_for_link_peer.

Tests:

- Three focused unit tests on handle_mtu_exceeded for the empty,
  tighten, and keep-tighter cases.
- Extended test_multihop_pmtud_heterogeneous_mtu to assert the
  lookup tightens after the wire-level MtuExceeded propagation,
  alongside its existing PathMtuState assertion.

Adds two #[cfg(test)] accessors on Node (path_mtu_lookup_get /
path_mtu_lookup_insert) and bumps handle_mtu_exceeded to
pub(in crate::node) for direct test invocation.
2026-05-02 18:30:09 +00:00
Johnathan Corgan ae607431eb Per-destination TCP MSS clamping at the TUN boundary
Adds source-side TCP MSS clamping informed by per-destination path
MTU learned via discovery, with a conservative IPv6-minimum-derived
ceiling for cold flows where discovery has not yet completed. Closes
the multi-hop default-config TCP wedges observed in production where
a sender's local-floor MSS exceeds what some intermediate forwarder
hop is willing to carry: silent drops, no PTB feedback through the
userspace TUN to the kernel TCP stack, retransmits at the same too-
large MSS, application connection times out.

## Architecture

A new `Arc<RwLock<HashMap<FipsAddress, u16>>>` field
`path_mtu_lookup` on Node mirrors the per-destination path MTU in a
form accessible from sync TUN reader/writer threads. A new
`per_flow_max_mss` helper in `src/upper/tun.rs` reads the lookup at
SYN-clamp time and returns the appropriate ceiling for the flow.

Three write sites populate `path_mtu_lookup`:

1. **Discovery originator branch** of `handle_lookup_response`:
   the path MTU bottleneck accumulated through the reverse path
   lands here when a LookupResponse arrives at the originator.
   Same value also lands in `coord_cache` per the existing
   `insert_with_path_mtu` API.

2. **FMP peer-promotion seed** (`seed_path_mtu_for_link_peer`):
   when an FMP link-layer peer is promoted to active, the local
   outgoing-link MTU on the peer's transport seeds the lookup.
   Tighter existing values (learned via discovery) are preserved;
   the seed only writes when no entry exists or the existing
   value is looser than the link MTU. Without this seed,
   directly-configured peers (auto_connect / static peer config)
   would leave `path_mtu_lookup` empty for their FipsAddress
   because the FSP session establishes without ever issuing a
   LookupRequest.

3. **Target-edge fold at `send_lookup_response`**: when a node is
   the discovery target, it folds its own outgoing-link MTU to
   the response's next-hop into `path_mtu` before sending.
   Without this fold, the response leaves the target with
   `path_mtu = u16::MAX` and only intermediate transits min-fold;
   the target's first reverse-path hop is never represented in
   the bottleneck calculation. Refactored the existing transit-
   side min-fold into a shared `apply_outgoing_link_mtu_to_response`
   helper called from both sites.

## Read-side: per_flow_max_mss

Two TUN call sites consume the lookup:

- Outbound `handle_tun_packet` clamps SYN MSS using packet[24..40]
  (IPv6 destination) as the lookup key.
- Inbound `TunWriter::run` clamps SYN-ACK MSS using packet[8..24]
  (IPv6 source).

When the lookup contains a learned value, the helper computes
`min(global_max_mss, effective_ipv6_mtu(path_mtu) - 60)` where 60
is IPv6 (40) + TCP (20) headers and `effective_ipv6_mtu` accounts
for the FIPS encapsulation overhead.

When the lookup is empty for a destination — the cold-flow case —
the helper returns `min(global_max_mss, IPv6-minimum-derived
ceiling)`. RFC 8200 mandates every IPv6 path accept ≥1280-byte
packets, so the IPv6-minimum-derived MSS (1280 - 77 - 60 = 1143)
fits any compliant path. Without this conservative ceiling, the
first SYN to a destination with no learned path MTU exits the TUN
at the kernel-natural MSS (TUN MTU - 60), and the application
connection wedges silently before discovery completes for a
corrected second SYN to fire. The fix is provably safe: the
ceiling is taken with `min` against the local global so operators
with even tighter local floors are never loosened upward.

Subsequent flows pick up the actual learned per-destination value
once discovery (or the FMP-promotion seed for direct peers)
populates the lookup.

## Diagnostic logging

All write and read sites emit instrumentation suitable for
operators bisecting a wedged path:

- `debug!` log on every `path_mtu_lookup` write (discovery
  originator path and FMP-promotion seed path), showing the
  FipsAddress, written value, prior value, and post-write map
  size. `warn!` on poisoned-lock failure path.
- `trace!` log per `per_flow_max_mss` call covering every
  fall-through branch (wrong addr_bytes length, non-fd::/8
  prefix, lookup poisoned, no entry for destination, empty-lookup
  conservative ceiling) and the success path. trace level filters
  out under normal log settings; capture with
  `RUST_LOG=info,fips::node::handlers::discovery=debug,fips::upper::tun=trace`.

## Tests

15 new unit tests across 3 files:

- `per_flow_max_mss` (8 tests in `src/upper/tun.rs::tests`):
  empty-lookup conservative ceiling, empty-lookup global-smaller
  floor, learned-value-overrides-conservative, per-destination
  smaller, per-destination larger capped by global, non-fips
  addr, short addr slice, per-destination independence.
- `seed_path_mtu_for_link_peer` (4 tests in
  `src/node/tests/unit.rs`): seed when empty, keep tighter
  existing, tighten looser existing, no-op for unknown
  transport.
- Discovery integration (3 tests in `src/node/tests/discovery.rs`):
  apply_outgoing_link_mtu_to_response on unknown peer no-op,
  two-node target-edge fold (path_mtu reflects target-edge link),
  three-node chain transit min-fold (existing test, updated for
  target-edge inclusion).

Two pre-existing discovery tests had assertions updated to
account for the target-edge fold:

- `test_response_path_mtu_two_node`: previously asserted
  `u16::MAX` (no transit to min-fold); now asserts 1280 (the
  test transport MTU, folded in by send_lookup_response).
- `test_response_path_mtu_four_node_chain`: previously asserted
  1350 (transit MTUs only); now asserts 1280 (target-edge MTU
  is the bottleneck).
- `test_transit_forwards_when_mtu_sufficient`: previously
  asserted 1400 (transit MTU only); now asserts 1280 (target-
  edge MTU is the bottleneck).

## Verification

Local CI on this commit: 29/29 suites pass, 1105 lib tests pass,
clippy --all-targets --all-features -D warnings clean, cargo fmt
clean. Production deploy verified via trace capture across the
managed fleet: cold-flow conservative ceiling branch fires on
first SYN, learned-lookup branch takes over once discovery
completes, both behaviors observable end-to-end at the SYN MSS
on the wire.

No wire-format change. No config-format change.
2026-05-02 17:37:07 +00:00
Johnathan Corgan 8448e38510 Make Node::transport_mtu() deterministic across restarts (TCP black hole fix)
Default-config TCP flows between fips peers were stalling completely
(cwnd-pinned, 0 bps for 10s+) on a non-trivial fraction of restarts.
Reproducible with iperf3 between any two peers.

Root cause: `Node::transport_mtu()` iterated `self.transports.values()`
(HashMap with default RandomState hasher) and returned `handle.mtu()`
of the first one whose `is_operational()` returned true. Two stacked
sources of non-determinism stacked on each other: HashMap iteration
order is randomized per-process via RandomState, and async transport
`.start()` completion order races each daemon restart.

The returned value drives the TCP MSS clamp ceiling computed once at
TUN init (src/upper/tun.rs:501-524) and stored as immutable max_mss
in the reader/writer thread state. When the picker landed on a
transport with MTU > 1357 (any non-UDP-1280 in the standard fleet
defaults), `max_mss > 1220` (kernel's natural fips0-MTU-derived MSS),
the daemon's clamp was silently a no-op, and the kernel emitted
1220-byte segments. Those wrap into 1280-byte IPv6 → 1357-byte fips
datagrams that exceed UDP-1280 transports at any forwarding hop,
causing silent drops with no PTB feedback to the kernel TCP stack.

Fix: return min across operational transports instead of first-iterated.
With UDP-1280 in the configured set (the common case),
`transport_mtu = 1280`, `max_mss = 1143 < 1220`, daemon's clamp
engages, MSS=1143 reaches the wire, packets fit, throughput recovers.

Empirical green light from a single-UDP-config end-to-end test:
iperf3-without-`-M` recovered to ~21 Mbps with no operator-side nft
TCPMSS rules.

Adds three unit tests:
- transport_mtu_returns_min_across_operational: pin selection to
  smallest MTU when multiple operational transports differ.
- transport_mtu_fallback_when_no_operational_transports: 1280 fallback.
- transport_mtu_min_with_single_operational: trivial single-transport
  case.

The `effective_ipv6_mtu` field reported by `fipsctl show status` was
also racy (consequence of the same bug); fixed by this change as a
side effect.
2026-05-02 01:27:15 +00:00
Johnathan Corgan ab2edec2c6 Add Nostr open-discovery startup sweep with diagnostic logging
Under `node.discovery.nostr.policy: open`, the per-tick auto-dial in
`queue_open_discovery_retries` was supposed to pick up adverts cached
from the relay subscription backlog at startup, but in practice only
adverts arriving live (after the daemon was up) were being dialed.
Backlog adverts sat in the in-memory cache until they aged out.

Adds a one-shot startup sweep that runs once per daemon start, gated
identically to the per-tick sweep (`enabled` && `policy == open`),
after a configurable settle delay so the relay subscription backlog
has time to populate the advert cache. The sweep iterates the cache
with the same skip-filters as the per-tick path (statically-configured
peers, already-connected, retry-pending, connecting) plus a tighter
age filter: only adverts whose `created_at` is within
`startup_sweep_max_age_secs` of now are queued.

Two new config fields under `node.discovery.nostr`:
- `startup_sweep_delay_secs` (default 5)
- `startup_sweep_max_age_secs` (default 3600 = one hour)

Both are only consulted when `policy == open`; under any other
policy the sweep is a no-op.

Adds diagnostic logging to the open-discovery sweep so operators can
verify what the auto-dial path is doing on each daemon bring-up:
info-level on each retry-queued enqueue (with peer short-npub and
advert age), and a one-line summary on every startup sweep and on
any per-tick sweep that queues at least one retry. The summary
breaks down skipped candidates by reason (age, configured, self,
already-connected, retry-pending, connecting, no-endpoints,
invalid-npub) — currently the path was silent so there was no
operator-visible signal that the cache iteration was running.

Refactors the existing `queue_open_discovery_retries` body into a
shared `run_open_discovery_sweep(max_age_secs, caller)` helper so
the per-tick and startup paths share filter/queue logic and only
differ in the age filter and log label. Surfaces `created_at` from
`NostrDiscovery::cached_open_discovery_candidates` (return tuple
extended) so the age filter has the data it needs.

Three new unit tests in `config::node::tests` cover the new defaults,
YAML override round-trip, and partial-YAML default fallback.
2026-05-01 18:09:50 +00:00
Johnathan Corgan e641eb5b5f Drop the nostr-discovery cargo feature flag
Make Nostr-mediated overlay discovery unconditional, mirroring the
philosophy of PR #79's collapse of the tui/ble/gateway features in
favor of platform cfg gates. nostr / nostr-sdk are pure Rust over
WebSockets/TCP, so they build cleanly on every FIPS-supported
platform — there is no need for the parallel feature gate.

The flag was already in `default = [...]`, so no behavior change for
anyone using `cargo build` without `--no-default-features`. Operators
who explicitly disabled the feature will now find Nostr code present
in the binary; the runtime check `node.discovery.nostr.enabled` still
controls whether the runtime starts.

Cargo.toml:
- Remove the `[features]` table entirely.
- Drop `optional = true` from `nostr` and `nostr-sdk`.

Source: 27 cfg sites collapsed across 5 files —
`src/discovery.rs`, `src/discovery/nostr/mod.rs`,
`src/node/handlers/rx_loop.rs`, `src/node/lifecycle.rs`,
`src/node/mod.rs`. Two `#[cfg(not(feature = "nostr-discovery"))]`
fallback blocks (the udp:nat-without-runtime debug-log path and the
"feature not compiled in" warning at startup) were removed as dead
code; the always-on path already handles the missing-runtime case
via `nostr_discovery: Option<NostrDiscovery>`.

Packaging and tooling:
- `packaging/openwrt-ipk/Makefile`: drop a stale `--features gateway`
  flag (the `gateway` feature was already removed in PR #79; this
  was a leftover that the build path tolerated only because cargo
  ignored unknown feature names).
- `testing/scripts/build.sh`: drop `DEFAULT_CARGO_BUILD_ARGS=(--features
  nostr-discovery)`; defaults are empty.
- `packaging/common/fips.yaml`: drop the "requires the
  nostr-discovery feature" comment from the discovery section.

Bundled cleanup:
- Apply `cargo clippy --fix` against three pre-existing warnings in
  `src/discovery/nostr/runtime.rs` and `src/discovery/nostr/stun.rs`
  (collapsed `if let Some` chain; two redundant `as i32` casts).
  These were always present but masked when the feature gate was
  off; they surface now that the code is unconditionally compiled.
- `cargo fmt` settled two minor formatting drift sites in
  `src/bin/fips-gateway.rs` and `src/config/mod.rs`.

Tests: 1083 passed, 0 failed, 4 ignored. clippy clean. fmt clean.
2026-04-30 10:24:32 +00:00
34e00b9f6e Add Nostr-mediated overlay discovery and UDP NAT traversal (#53)
Optional peer discovery and NAT hole-punching path gated behind a new
`nostr-discovery` cargo feature. Nodes publish signed overlay endpoint
adverts to public Nostr relays, consume peer adverts to populate
fallback dial addresses, and use STUN-assisted UDP hole punching with
NIP-59 gift-wrap offer/answer signaling to establish direct UDP paths
between NATed peers. Once a punched socket is up, it is handed into
the existing FIPS UDP transport and the standard Noise/FMP session
stack takes over unchanged.

The cargo feature is in the default feature set
(`default = ["nostr-discovery"]`) so stock builds include it; a
build that explicitly disables default features (or selects a
feature set without `nostr-discovery`) does not link the nostr /
nostr-sdk crates and does not emit a no-op poll in the tick loop.
Runtime behavior is independently gated by
`node.discovery.nostr.enabled`, which defaults to false; if the
config enables Nostr on a non-feature build, startup logs a
warning and continues without it.

== Cargo feature and dependencies

- New cargo feature `nostr-discovery = ["dep:nostr", "dep:nostr-sdk"]`.
  Not in the default feature set.
- New optional Linux-only dependencies: `nostr 0.44` (features: std,
  nip59) and `nostr-sdk 0.44`. Gift-wrap unwrap is hand-rolled in
  `src/discovery/nostr/signal.rs` rather than relying on the SDK's
  rumor-author check, which FIPS sidesteps by trusting `seal.pubkey`
  exclusively.

== Wire format

Overlay advert event: `kind 37195`, parameterized replaceable
(NIP-01 application-defined replaceable range 30000-39999), with
`d = "fips-overlay-v1"`. The digits visually spell FIPS (7=F, 1=I,
9=P, 5=S); a relay survey confirmed the kind is unused.

Advert content carries the version tag, endpoint list
(`udp|tcp|tor` + addr), optional signal-relay and stun-server
metadata, and `issuedAt` / `expiresAt` timestamps. Endpoint
`addr: "nat"` is the sentinel that triggers traversal on the peer
side. NIP-40 `expiration` tag bounds staleness on permanent
shutdown. Lifecycle relies on parameterized-replaceable
supersession; the daemon does not emit NIP-09 kind-5 deletes —
strict relays (Damus, Primal) race delete-against-replace and can
silently drop the replacement.

Gift-wrapped signal event: `kind 21059`. Punch packets carry magic
values `PUNCH_MAGIC` / `PUNCH_ACK_MAGIC`, a sequence number, and a
16-byte session hash.

== Discovery surface

- `src/discovery.rs` (always compiled)
  - `EstablishedTraversal`: bound UDP socket + selected remote +
    peer npub + optional transport name/config tuning overrides.
  - `BootstrapHandoffResult`: returned on successful handoff —
    allocated transport id, local/remote addrs, peer NodeAddr,
    session id.
- `src/discovery/nostr/` (`#![cfg(feature = "nostr-discovery")]`)
  - `types.rs`: wire and control types described above. `ADVERT_KIND`
    constant. `BootstrapError` enumerates failure modes (disabled,
    missing advert, missing NAT endpoint, no usable relays, invalid
    advert, invalid npub, signal timeout, punch timeout, replay,
    STUN failure, protocol, nostr, io, serde, event-parse).
  - `runtime.rs`: `NostrDiscovery` coordinator. Owns the shared
    nostr-sdk `Client`, subscribes to advert + signal event kinds,
    maintains a bounded advert cache and a bounded seen-sessions
    replay set, drains `BootstrapEvent::{Established, Failed}` for
    the node to consume, exposes `update_local_advert`,
    `request_connect`, `advert_endpoints_for_peer`,
    `cached_open_discovery_candidates`, and `shutdown`.
  - `signal.rs`: NIP-59 gift-wrap encode/decode. Outbound wraps are
    built against per-attempt ephemeral keys; inbound events are
    unwrapped against the node identity.
  - `stun.rs`: RFC 5389/8489 Binding Request client with
    XOR-MAPPED-ADDRESS parsing for both IPv4 and IPv6; used only to
    observe the initiator's own reflexive address against its
    locally configured STUN list (peer-advertised STUN is
    informational, never an egress target).
  - `traversal.rs`: per-attempt candidate-pair punch planner.
    Allocates a fresh `0.0.0.0:0` UDP socket per attempt, enumerates
    LAN-private and ULA interface addresses alongside the STUN
    reflexive address, schedules probe/ack exchanges at the
    configured interval for the configured duration, and picks the
    first candidate pair that authenticates end-to-end.

Strategy ordering is Reflexive↔Reflexive first, then LAN, then
Mixed. The STUN-observed pair is the only candidate that's reliable
across arbitrary network topologies; trying it first prevents the
planner from latching onto a misleading host-candidate path before
the reflexive path gets a chance. There is no catch-all
Local↔Local strategy: a previous design that paired every local
host candidate from one side with every local host candidate from
the other could declare success on a one-way reachable asymmetric
L3 path (corporate VPN, Tailscale subnet route, overlapping private
address space), only for the FMP handshake to stall because the
return path didn't match. The legitimate `Lan` strategy still pairs
candidates that share a subnet.

== Configuration surface

`node.discovery.nostr.*` (`NostrDiscoveryConfig`), all `serde(default)`
with `deny_unknown_fields`:

- `enabled` (default false), `advertise` (default true)
- `advert_relays`, `dm_relays`, `stun_servers`: defaults are
  `wss://relay.damus.io`, `wss://nos.lol`, `wss://offchain.pub`
  for both relay lists, and Google / Cloudflare / Twilio for STUN.
  Operators are expected to override for production. Other
  verified-working public relays for reference:
  `nostr.bitcoiner.social`, `nostr-pub.wellorder.net`,
  `nostr.oxtr.dev`, `nostr.mom`.
- `app` (default `"fips-overlay-v1"`), `signal_ttl_secs` (120)
- `policy`: `NostrDiscoveryPolicy::{Disabled, ConfiguredOnly (default),
  Open}` — controls whether advert-derived endpoints are consumed
  only for peers carrying `via_nostr = true`, or also for
  non-configured peers within a budget cap.
- `share_local_candidates` (default false) — when false, the offer's
  `local_addresses` list is empty and peers see only the reflexive
  address. Enable per-node only for genuinely same-LAN deployments;
  off-by-default eliminates the misleading-path failure mode for
  the common case where peers are not on the same broadcast domain.
- `open_discovery_max_pending` (64) — caps queued open-discovery
  retries; bounded by available outbound slots.
- `max_concurrent_incoming_offers` (16) — semaphore against offer
  spam; excess offers are debug-logged and dropped.
- `advert_cache_max_entries` (2048) and `seen_sessions_max_entries`
  (2048) — bound memory under ambient relay volume; overflow
  evictions are debug-logged.
- `attempt_timeout_secs` (10), `replay_window_secs` (300)
- `punch_start_delay_ms` (2000), `punch_interval_ms` (200),
  `punch_duration_ms` (10000)
- `advert_ttl_secs` (3600), `advert_refresh_secs` (1800)

Per-peer and per-transport flags:

- `PeerConfig.via_nostr: bool` — when true (and Nostr is enabled),
  advert-derived addresses are appended as fallback dial candidates
  after static addresses for that peer.
- `PeerConfig.addresses` is now `serde(default)` and may be empty
  when `via_nostr: true`; validation requires at least one of the
  two to be present per peer, and the error message names the
  peer's npub.
- `UdpConfig.advertise_on_nostr: Option<bool>` and
  `UdpConfig.public: Option<bool>` — UDP transports can be
  advertised either as direct `host:port` (public = true) or as the
  `addr: "nat"` sentinel that triggers rendezvous on the peer side.
- `TcpConfig.advertise_on_nostr` and `TorConfig.advertise_on_nostr`
  — TCP and Tor onion endpoints can be advertised as directly
  reachable.
- A reserved peer address `transport: udp, addr: "nat"` parses without
  special-casing in YAML and routes through the bootstrap runtime.

Cross-field validation (`Config::validate`, called from `Node::new`
and `Node::with_identity`):

- Any transport with `advertise_on_nostr = true` requires
  `node.discovery.nostr.enabled = true`.
- Any peer with `via_nostr = true` requires
  `node.discovery.nostr.enabled = true`.
- A non-public UDP advert (`advertise_on_nostr = true`,
  `public = false` — i.e. `udp:nat`) additionally requires at least
  one `dm_relay` and at least one `stun_server`.
  Surfaced as `ConfigError::Validation`.

== Node integration

`src/node/lifecycle.rs` is the main integration point.

- At node start (after transports are up, before TUN), if Nostr is
  enabled and the feature is compiled in, `NostrDiscovery::start` is
  invoked, the initial local overlay advert is built from the live
  transport set and published, and the runtime handle is stored.
- The rx tick loop calls `poll_nostr_discovery` (feature-gated both
  at method definition and call site), which refreshes the local
  advert, drains bootstrap events, adopts established traversals,
  schedules retries for failed traversals, and — under `policy:
  open` — enqueues outbound retries for non-configured peers
  visible in the advert cache, bounded by
  `open_discovery_max_pending` and the remaining outbound slots.
- Outbound peer dialing is refactored to `try_peer_addresses`, which
  first exhausts the static address list in priority order and only
  then appends advert-derived fallback addresses; both lists run
  through the same `attempt_peer_address_list` code path. The
  `udp:nat` sentinel address triggers `NostrDiscovery::request_connect`
  for the peer instead of a direct dial and returns `Ok(())`.
- `build_overlay_advert` walks operational transports, consults
  per-instance `UdpConfig` / `TcpConfig` / `TorConfig` (matching by
  optional transport instance name), and emits an `OverlayAdvert`
  including `signalRelays` and `stunServers` when any UDP endpoint
  is advertised as NAT.
- `adopt_established_traversal` is the bootstrap handoff API:
  allocates a new `TransportId`, constructs a `UdpTransport` with
  the user-supplied (or default) `UdpConfig`, calls the new
  `adopt_socket_async` to reuse the punched socket verbatim,
  registers the transport in the normal transport map, records it
  in `bootstrap_transports`, and calls `initiate_connection` so the
  normal handshake path runs. On failure, the transport is stopped
  and removed cleanly and the set membership is rolled back.
- On clean shutdown, `NostrDiscovery::shutdown` is awaited so
  background tasks stop before transports are torn down. (The
  advert is not explicitly retracted; NIP-40 expiration plus the
  next refresh from any live publisher supersedes it.)

New `Node` fields:

- `nostr_discovery: Option<Arc<NostrDiscovery>>` (feature-gated).
- `bootstrap_transports: HashSet<TransportId>` — per-peer UDP
  transports adopted from NAT traversal, cleaned up via
  `cleanup_bootstrap_transport_if_unused` whenever the link,
  connection, peer, or pending-connect referencing them is removed.

Retry and error surface:

- `RetryState.expires_at_ms: Option<u64>` — optional absolute expiry
  for a retry entry. `pump_retries` drops expired entries with an
  info log. Used for open-discovery retries, which expire at two
  times the advert TTL.
- New `NodeError::BootstrapHandoff(String)` returned from
  `adopt_established_traversal` when the underlying transport
  adoption fails or local address discovery fails.
- New `ConfigError::Validation(String)`.
- A small refactor extracts `Node::now_ms()` and reuses it across
  lifecycle, rx-loop tick, and timeout bookkeeping.

== UDP transport

`src/transport/udp/`:

- `UdpRawSocket::adopt(std::net::UdpSocket, recv_buf, send_buf)`:
  adopts an externally bound socket, makes it non-blocking, applies
  the configured buffer sizes (warning if the kernel clamps), and
  reports the resulting local address. Preserves the NAT mapping —
  no rebind.
- `UdpTransport::adopt_socket_async(std::net::UdpSocket)`: the
  `start_async` analogue for an already-bound socket, wiring the
  async socket and recv task exactly as the fresh-bind path would.
- `Drop` impl for `UdpTransport`: if a transport is dropped while
  still holding a recv task or socket (for example on error
  teardown), aborts the task, clears the socket, and emits a debug
  log so the cleanup is visible in tracing rather than silent.

== Logging and observability

Default `EnvFilter` demotes third-party relay-pool DEBUG output to
TRACE-only: `nostr_relay_pool`, `nostr_sdk`, and `nostr` are pinned
at INFO when our level is anything below TRACE, and at TRACE when
our level is TRACE — so the raw frames are still reachable when
explicitly asked for. RUST_LOG continues to override completely.

Concise one-line DEBUG events are emitted at the meaningful points
in the discovery / hole-punch sequence:

- `advert: published` (event id, relay count, endpoints, ttl)
- `advert: peer cached` (notify-loop ingress for non-self)
- `advert: resolved` (cache hit / relay fetch outcome)
- `traversal: initiator starting`
- `traversal: initiator STUN observed` (reflexive, local count)
- `traversal: offer sent` (session id, relay count, event id)
- `traversal: answer received` (accepted, reflexive, local)
- `traversal: initiator punch succeeded` (remote addr)
- `traversal: offer received` (responder side)
- `traversal: responder STUN observed`
- `traversal: answer sent`
- `traversal: responder punch succeeded`

Npubs are shortened to `npub1<4>..<4>` and event/session ids to
their first 8 hex characters.

Other operator-facing logs:

- `UdpTransport` adoption and drop paths log at info / debug.
- `adopt_established_traversal` logs at debug on entry and info on
  successful return, tagged with peer npub, session id, transport
  id, and both socket endpoints, so the bootstrap handoff is
  traceable end-to-end alongside the `UdpTransport::drop` log.
- `cleanup_bootstrap_transport_if_unused` logs at debug when the
  reference-count check drops an adopted transport.
- `connect_peer` tags its entry `debug!` with `peer_npub` so
  downstream STUN, punch, and handshake logs for the same peer
  correlate for operators.
- Advert-cache and seen-sessions overflow evictions log at debug so
  mis-sized caps are visible under ambient relay volume.
- Gift-wrap unwrap failures on `SIGNAL_KIND` events log at trace
  (hot path: fires for every unrelated signal event on the same
  relay).
- Traversal-offer handler failures log at debug. Expected conditions
  such as punch timeout on symmetric NAT are covered there; real
  problems are reported upstream via `BootstrapEvent::Failed`.
- Inbound-offer rate-limit messages name the governing config field
  (`max_concurrent_incoming_offers`) and state that the offer was
  rate-limited rather than failing.

== Tests

- 18 new unit tests in `src/discovery/nostr/tests.rs` covering advert
  encoding, signal envelope round-trip, STUN parsing, punch-packet
  codec, and replay-window enforcement. Run under the
  `nostr-discovery` feature.
- Config-validation tests in `src/config/mod.rs` covering the three
  cross-field invariants and YAML parsing of the full
  `node.discovery.nostr` block plus `peers[].via_nostr`, empty
  `addresses` with `via_nostr: true`, and a `udp: nat` address.
- `src/node/tests/bootstrap.rs` integration tests that drive a
  synthetic traversal (bound UDP socket pair + synthetic peer
  identity) through `adopt_established_traversal` and assert the
  Noise handshake completes over the adopted socket.
- Punch-planner tests assert reflexive-before-LAN ordering and that
  same-LAN scenarios still include the LAN target in the plan.
- `testing/nat/` Docker NAT lab harness:
  - Local `strfry` relay, local STUN responder, and one or two
    router containers performing `iptables` NAT.
  - Node LAN interfaces are provisioned with explicit `veth` pairs
    injected into the node and router namespaces so every packet
    traverses the router namespace (plain Docker bridges are not
    used for the LAN).
  - `cone` scenario: both peers behind full-cone-emulation NAT
    (SNAT with source-port preservation, inbound DNAT back to the
    single LAN host regardless of remote source); asserts UDP
    traversal succeeds and link remote addresses are on the router
    WAN subnet.
  - `symmetric` scenario: `MASQUERADE --random-fully`; asserts UDP
    traversal fails and TCP fallback converges over router-
    published WAN addresses.
  - `lan` scenario: both peers share a LAN subnet; asserts LAN
    addresses are preferred over reflexive ones.
  - Cleanup tears down all profile-gated services
    (`--profile cone --profile symmetric --profile lan`) so no
    orphan containers survive a run.
- `testing/scripts/build.sh` builds the Docker test image with
  `--features "tui nostr-discovery"` by default so NAT-harness
  binaries include bootstrap support.

== CI

- Linux release build and nextest unit-test job both use
  `--features "gateway nostr-discovery"` so the feature-gated code
  and its unit tests compile and run in CI.
- Three new integration matrix entries (`nat-cone`, `nat-symmetric`,
  `nat-lan`) invoke `testing/nat/scripts/nat-test.sh`, collect
  `docker compose logs` on failure, and always stop containers.

== Packaging and operations

- `packaging/common/fips.yaml` ships a fully commented
  `node.discovery.nostr.*` block, plus documented
  `advertise_on_nostr` / `public` examples under the UDP transport,
  an `advertise_on_nostr` example under TCP, and a `via_nostr: true`
  example under the static peer section with both a direct
  `host:port` UDP address and a `udp: nat` fallback.
- `.github/workflows/package-openwrt.yml`: NIP-94 release event
  publishes target the new default relay set.

== Documentation

- `README.md`: overlay discovery + NAT traversal moved from
  "Near-term priorities" into "What works today".
- `docs/design/fips-intro.md`: rewrites the paragraphs that
  previously described Nostr discovery and NAT traversal as future
  work; describes the shipped mechanism and the feature gate.
- `docs/design/fips-transport-layer.md`: drops the "(future
  direction)" qualifier from the Nostr Relay Discovery section,
  expands with the `udp:nat` advertisement and bootstrap handoff
  description, and updates the Current State callout.
- `docs/design/fips-mesh-layer.md`: notes that mid-session NAT
  rebinding (roaming) and initial NAT traversal (Nostr path) are
  distinct mechanisms.
- `docs/design/fips-configuration.md`: documents the full
  `node.discovery.nostr.*` surface, including the three resource
  caps and `share_local_candidates`.
- `docs/design/fips-nostr-discovery.md`: design and configuration
  reference for the shipped mechanism, including the empty-
  `addresses`-with-`via_nostr` shorthand.
- `docs/proposals/nostr-udp-hole-punch-protocol.md`: adds an
  Implemented status callout, clarifies that the punch socket is
  per-peer and per-attempt rather than shared with the application
  listener, aligns field names with the shipped JSON
  (`sessionId`, `issuedAt` / `expiresAt`, `reflexiveAddress`,
  `localAddresses`, `stunServer`), sets the `d`-tag to
  `fips-overlay-v1`, names the kind as 37195, and notes that
  advertised STUN entries are informational.
- `docs/proposals/README.md`: adds a Status column and marks the
  hole-punching proposal Implemented.
- `CHANGELOG.md`: Unreleased > Added entry covering the discovery
  path, STUN/punch path, configuration surface, and Docker NAT lab.

Co-authored-by: Johnathan Corgan <johnathan@corganlabs.com>
2026-04-27 08:15:58 -07:00
Johnathan Corgan f16b837a12 Tune overly aggressive discovery rate limiting
The default 30s post-failure backoff (300s cap, doubling per
consecutive failure) was set to bound traffic from chatty apps
looking up unreachable targets, but in practice it dominates
cold-start mesh convergence: a single timed-out lookup during
initial bloom-filter propagation suppresses any retry for 30s, and
the existing reset triggers (parent change, new peer, first RTT,
reconnection) don't fire on a stable post-handshake topology. The
suppression window winds up dictating the protocol's effective
time-to-converge instead of bounding repeat traffic.

Replaces the single-lookup-with-internal-retry model
(`timeout_secs`/`retry_interval_secs`/`max_attempts`) with a
per-attempt timeout sequence in `node.discovery.attempt_timeouts_secs`,
defaulting to `[1, 2, 4, 8]`. Each attempt sends a fresh LookupRequest
with a new random request_id so successive attempts can take different
forwarding paths as the bloom and tree state evolve. The destination
is declared unreachable only after the sequence is exhausted (15s
total at the default).

Disables post-failure suppression by default (`backoff_base_secs`/
`backoff_max_secs` now `0`/`0`). The `DiscoveryBackoff` machinery
stays in tree (inert at zero base/cap); operators with chatty apps
generating repeat lookups against unreachable destinations can opt
back in.

`PendingLookup` field shape unchanged so the control-socket
`show_routing` JSON (`pending_lookups[].attempt`/`initiated_ms`/
`last_sent_ms`) keeps the same schema for fipstop and external
consumers; `last_sent_ms` now means "current-attempt start" under
the new state machine.
2026-04-26 19:12:19 +00:00
Johnathan CorganandGitHub cbc78091ab Rationalize cargo feature and platform-gate surface (#79)
Drop the `tui`, `ble`, and `gateway` cargo features and replace
them with platform cfg gates. Plain `cargo build` now produces
every subsystem appropriate for the target platform with no
feature flags required.

Motivation:
- `default = ["tui", "ble"]` broke `cargo build` on macOS and
  Windows because `ble` pulled in `bluer` (BlueZ, Linux-only).
  Every non-Linux packager needed `--no-default-features`.
- The feature flags on `ble` and `gateway` were redundant with
  their platform-gated deps (`bluer`, `rustables`). The parallel
  gating was inconsistent and error-prone.
- `tui` feature protected against a ratatui binary-size concern
  that no longer applies in 2026.

Cargo.toml:
- Remove `tui`, `ble`, `gateway` features; `default = []`.
- Promote `ratatui` to a non-optional top-level dependency.
- Move `rustables` from top-level optional into the Linux
  target block, non-optional.
- Split `bluer` into its own target block with
  `cfg(all(target_os = "linux", not(target_env = "musl")))`
  — BlueZ isn't available on musl router targets and
  `libdbus-sys` doesn't cross-compile to musl without pkg-config
  sysroot setup.
- Drop `required-features` from the `fipstop` and `fips-gateway`
  `[[bin]]` entries.

build.rs:
- Emit a `bluer_available` custom cfg when `target_os == "linux"`
  and `target_env != "musl"`, for use in place of the verbose
  full predicate in source cfg gates.

Source:
- Replace every `#[cfg(feature = "gateway")]` with
  `#[cfg(target_os = "linux")]`. Gateway code works on both
  glibc and musl Linux (rustables is fine on musl).
- Replace every `#[cfg(feature = "ble")]` with
  `#[cfg(bluer_available)]`. BLE-specific code (BluerIo module,
  bluer type conversions, BLE transport instance creation,
  resolve_ble_addr) is excluded on musl and non-Linux. Generic
  `BleAddr`, `BleIo` trait, `MockBleIo`, and `BleTransport<I>`
  still compile on all targets.
- `src/bin/fips-gateway.rs`: always compiled, but `main()` is
  gated to Linux. Non-Linux stub exits 1 with a diagnostic.
  Existing non-Linux packaging scripts don't ship it, so the
  stub binary sits unused.

Packaging and CI:
- Drop `--features` and `--no-default-features` flags from every
  packaging script and workflow. Defaults now match each
  platform's capabilities.
- AUR `fips-git` automatically aligns with stable `PKGBUILD`
  (both build with defaults).

Verified: `cargo build --release` with no flags produces all
four binaries on glibc Linux; all unit and integration tests
pass across Linux/macOS/Windows/OpenWrt (musl) in CI.
2026-04-24 13:42:30 -07:00
Johnathan Corgan 03f6db58e8 Merge branch 'maint' 2026-04-21 19:33:19 +00:00
Johnathan Corgan db4b32110c Validate bloom filter fill ratio on FilterAnnounce ingress
A malformed FilterAnnounce whose fill ratio produces an implausibly
high false-positive rate is mostly useless for routing and, once
merged into our outgoing filter via bitwise OR, propagates the
saturated state to tree peers one hop per announce tick. A saturated
filter also made estimated_count() return f64::INFINITY, which
compute_mesh_size summed into its cached estimate.

handle_filter_announce now rejects inbound FilterAnnounce whose
derived FPR exceeds `node.bloom.max_inbound_fpr` (new config field,
default 0.05 ≈ fill 0.549 at k=5). Rejection is silent on the wire,
logs at WARN, and increments a new `bloom.fill_exceeded` counter. The
peer's prior stored filter and filter_sequence are left unchanged so
a single rejected announce does not wipe the peer's existing
contribution to aggregation.

After a successful outgoing FilterAnnounce send, a rate-limited WARN
fires if our own filter's FPR exceeds the same cap, surfacing
aggregation drift. Limited to once per 60 seconds via a new
Node.last_self_warn field.

BloomFilter::estimated_count() now takes max_fpr and returns
Option<f64>. Returns None for saturated filters (regardless of cap)
or when the filter's FPR exceeds max_fpr. Callers updated: debug
logs render None as "—", the Debug impl uses f64::INFINITY as "no
cap" and prints "saturated" instead of inf, control-socket JSON
emits null, and compute_mesh_size propagates None into the already-
Option<u64> estimated_mesh_size field.
2026-04-21 19:28:23 +00:00
Alex XieandJohnathan Corgan 745b523ac6 Add peer ACL enforcement with reloadable allow/deny files (#50)
Implement TCP Wrappers-style peer access control using
/etc/fips/peers.allow and /etc/fips/peers.deny files. Evaluation
order: allow overrides deny, default permit when no files exist.

Three enforcement points: outbound connect (before dialing), inbound
handshake (msg1 receipt, after restart/rekey classification), and
outbound handshake completion (msg2, before peer promotion). Files
support npub, hex pubkey, host alias, and ALL wildcard entries with
automatic mtime-based reload.

Adds fipsctl acl show query, 954-line acl module with unit tests,
and a 6-node Docker integration harness (testing/acl-allowlist/)
exercising insider, outsider, and allowed-remote scenarios. CI
matrix entry included.

Closes #50

Co-authored-by: Johnathan Corgan <johnathan@corganlabs.com>
2026-04-16 05:13:07 +00:00
Johnathan CorganandGitHub 5abae0859e Add historical node and per-peer statistics with btop-style graphs (#64)
In-memory time-series history on the daemon: fast ring (1s × 3600)
plus slow ring (1m × 1440) per metric, covering node-level gauges
(mesh size, tree depth, peer count, active sessions), counters
(parent switches, aggregate bytes/packets in/out), loss rate, and
seven per-peer metrics keyed by NodeAddr (srtt_ms, loss_rate,
bytes_in/out, packets_in/out, ecn_ce). The slow ring is produced by
downsampling the fast ring on minute boundaries with Last / Sum /
Mean aggregation chosen per metric type.

Missing data is first-class. New peers back-fill NaN so every ring
shares a time axis with the node rings; peers absent from a tick
sample NaN (keeps alignment, shows as a visible gap); counter metrics
emit NaN on decrease (new link_stats baseline after reconnect) so
deltas aren't polluted. Peers are evicted 24h after last contact.
Downsampling is NaN-aware: mean skips NaN, all-NaN slow windows stay
NaN. Each history window always returns its full span at the chosen
density (1m / 10m / 1h / 24h), front-padded with NaN when the ring
hasn't yet accumulated enough samples, so switching between windows
feels like zooming in or out rather than clipping to whatever has
arrived. NaN serializes to JSON null via a custom serializer.

Control socket queries:
- show_stats_list enumerates registered metrics plus scope field and
  peer_retention_seconds.
- show_stats_history returns one metric's series for a given window
  and granularity; accepts optional peer (npub) for per-peer metrics.
- show_stats_all_history returns every metric in a single round trip;
  accepts optional peer to fetch all seven per-peer metrics.
- show_stats_peers enumerates tracked peers with lifecycle metadata.
- show_stats_history_all_peers returns one metric across all peers
  for grid rendering.
- show_status carries short sparkline windows for the dashboard so
  the client can render without extra fetches.

fipsctl gains `stats list`, `stats peers`, and `stats history
<metric>` with `--peer` (hostname or npub) and `--plot` for a Unicode
block sparkline. Plot header reports sample count, granularity,
window, and gap count; NaN renders as a blank cell.

fipstop dashboard grows inline sparklines (peer count, mesh size,
aggregate bytes in/out). A new Graphs tab stacks every metric as an
independent mini plot with its own autoscaled range; each plot uses
btop's braille 2×4 filled-area algorithm (25-entry lookup table
packing two samples per character, per-row gradient coloring for the
characteristic btop vertical-band look, rounded borders with embedded
titles). Three modes are cycled with `m`: Node (node-level stack),
MetricByPeer (small-multiples grid, 1 / 2 / 3 columns by terminal
width), PeerByMetric (existing stack scoped to one peer). `n` / `N`
cycles the mode-specific selector (metric or peer), a selector row
shows the current choice, and Graphs-tab refreshes re-fetch
show_stats_peers so selectors track peer churn. Up / Down scrolls
the stack, Left / Right cycles the window, `g` jumps to the tab.

Implements IDEA-0084 (TASK-2026-0062).
2026-04-14 10:24:16 +01:00
Tim O'SheaandJohnathan Corgan 2d342a4e47 Add diagnostic queries for security validation and mesh debugging
Extend the fipsctl control query interface with visibility into internal
state critical for protocol security auditing, mesh troubleshooting, and
operational monitoring.

New command:

  fipsctl show identity-cache

    Lists every node identity cached by the daemon (learned from DNS
    resolution, peer handshakes, sessions, and static config).  Shows
    npub, IPv6 address, display name, and LRU age alongside the
    configured cache capacity.

Extended queries:

  show peers — Noise session counters (send_counter, highest received
    counter) for rekey urgency assessment.  Per-peer replay suppression
    and consecutive decrypt failure counts for active attack detection.
    Session index visibility for hijack analysis.  Rekey lifecycle
    state (in_progress, draining, K-bit epoch).

  show sessions — Handshake resend count during establishment for
    connectivity debugging.  Rekey and session health fields
    (session_start, K-bit, coords warmup, drain state) when
    established.

  show cache — Individual coordinate cache entries with tree
    coordinates, depth, path MTU, and age.  Enables route-level
    debugging by showing exactly which destinations have cached
    routes and via what tree path.  Renames the top-level count
    field from "entries" to "count" for clarity.

  show routing — Pending discovery lookups expanded from count to
    per-target detail (attempt number, age, last sent).  Pending
    TUN packet queue depth for backpressure visibility.  Connection
    retry state per peer (retry count, next attempt, auto-reconnect
    flag).

Updates fipstop to match the revised show_cache and show_routing
response schemas.  Updates README monitoring section with the complete
fipsctl command list.

Co-authored-by: Johnathan Corgan <johnathan@corganlabs.com>
2026-04-13 17:34:01 +00:00
OceanSlimandGitHub 774e33fd27 Add Windows platform support (#45)
Gate platform-specific code behind cfg attributes and add full Windows
  support: TUN device via wintun, TCP control socket on localhost:21210,
  Windows Service lifecycle (--install-service/--uninstall-service/--service),
  CI build and test matrix, and packaging with ZIP builder and PowerShell
  service management scripts.

  Key changes:

  - Cargo.toml: move tun/libc/rtnetlink behind cfg(unix); add wintun and
    windows-service dependencies for Windows
  - upper/tun.rs: wintun-based TUN implementation with netsh configuration
    for IPv6 address, MTU, and fd00::/8 routing
  - control/mod.rs: split into unix_impl/windows_impl; Windows uses TCP on
    localhost:21210 with shared connection handler
  - bin/fips.rs: refactor main() into run_daemon() accepting a shutdown
    signal; add Windows Service support via windows-service crate
  - transport/udp/socket.rs: platform-gated modules; Windows uses
    tokio::net::UdpSocket (kernel drop count unavailable, returns 0)
  - transport/ethernet: gate to cfg(unix); add Windows stub types
  - config: platform-conditional default paths (socket, hosts) for Windows
  - CI: add windows-latest to build matrix and test-windows job with
    cargo-nextest
  - packaging/windows: build-zip.ps1, install-service.ps1,
    uninstall-service.ps1, and package-windows.yml workflow
  - README/docs: Windows build instructions, service management, and
    control socket platform differences

  Linux and macOS behavior is unchanged.
2026-04-11 18:31:48 +01:00
Johnathan Corgan e9da598f8a Apply rustfmt to master-only code 2026-04-10 08:47:02 +00:00
Johnathan Corgan 13c0b70dc3 Add rustfmt formatting policy and reformat codebase
Add rustfmt.toml with stable defaults and apply cargo fmt to all
source files. This establishes a consistent formatting baseline
for CI enforcement.
2026-04-10 08:27:07 +00:00
Origami74 e693f4fb7e Add macOS support, fix bloom filter routing and MMP intervals
macOS platform:
- Platform-native TUN interface management with shutdown pipe
- Raw Ethernet transport with macOS socket backend (socket_macos.rs)
- EthernetTransport and TransportHandle::Ethernet ungated from Linux-only
- macOS .pkg packaging (build-pkg.sh, launchd plist, uninstall script)
- CI: macOS build and unit test jobs; x86_64 cross-compiled from
  macos-latest via rustup target add x86_64-apple-darwin

Gateway feature flag:
- New opt-in `gateway` Cargo feature activates optional `rustables` dep
- `pub mod gateway` and `Config.gateway` gated behind the feature so
  macOS builds never pull in Linux-only nftables bindings
- `fips-gateway` bin has `required-features = ["gateway"]`
- All Linux/OpenWrt/AUR packaging passes `--features gateway`

CI / packaging:
- package-linux, package-macos, package-openwrt now trigger on push to
  master/maint/next and on pull requests; release uploads remain tag-gated
- Bloom filter routing fix: fall through to tree routing when no candidate
  is strictly closer
- MMP intervals: raise MIN to 1s / MAX to 5s with 5-sample cold-start phase
2026-04-09 20:03:42 +01:00
Johnathan Corgan aac96510d0 Merge branch 'maint' 2026-04-05 12:24:44 +00:00
Johnathan Corgan a859da7748 Fix bloom filter routing blocking greedy tree fallback
When bloom filter candidates existed but none were strictly closer to
the destination in tree-coordinate distance, find_next_hop returned
None without trying greedy tree routing. This caused NoRoute failures
in topologies where the tree parent was closer but not a bloom
candidate. Fall through to tree routing when no bloom candidate makes
progress.
2026-04-05 12:23:24 +00:00
Johnathan Corgan 89352d3218 Add BLE L2CAP transport with scan-based auto-connect
BLE transport implementation using L2CAP Connection-Oriented Channels
(SeqPacket mode) via the bluer crate, behind cfg(feature = "ble").

Core transport:
- BleTransport<I> generic over BleIo trait (BluerIo prod, MockBleIo test)
- Connection pool with priority eviction (static > discovered, max 7)
- Connect-on-send via connect_inline() matching TCP behavior
- Per-connection receive loops with pool cleanup on disconnect

Discovery and probing:
- Combined scan_probe_loop using select! over scanner events and a
  BinaryHeap delay queue with per-entry random jitter (0-5s) to prevent
  herd effects when multiple nodes see the same beacon simultaneously
- Pre-handshake pubkey exchange ([0x00][pubkey:32]) for IK identity
- Cross-probe tie-breaker: smaller NodeAddr's outbound wins (same
  convention as FMP/FSP rekey dual-initiation)
- Probed peers reported to DiscoveryBuffer; pool fills through normal
  node-layer auto-connect -> send_async -> connect_inline path

Beacon management:
- Periodic advertising: 1s burst every 30s (configurable via
  beacon_interval_secs / beacon_duration_secs)
- FIPS service UUID for scan filtering

Configuration (all fields optional with defaults):
- adapter, psm, mtu, max_connections, connect_timeout_ms
- advertise, scan, auto_connect, accept_connections
- beacon_interval_secs (30), beacon_duration_secs (1)

Hardware validated with two BLE nodes:
- 2048-byte MTU, ~60-160ms RTT, zero-config auto-connect
- BLE spike tool at testing/ble/ for standalone adapter validation

42 unit tests + 4 node-level integration tests, all CI-compatible
via MockBleIo (no hardware required). tokio test-util added for
time-dependent scan/probe tests.
2026-03-25 04:21:46 +00:00
Johnathan Corgan b8fbecc575 Demote 35 info-level log messages to debug for cleaner production output
Reduce info-level noise by moving intermediate steps, periodic
telemetry, cross-connection resolution details, and redundant messages
to debug. Info output now focuses on operator-relevant state changes:
lifecycle events, peer promotions, session establishment, parent
switches, and transport start/stop.

Key categories demoted:
- Handshake cross-connection resolution mechanics (10 messages)
- Periodic MMP link/session metric reports (4 messages)
- TUN cleanup messages redundant with lifecycle shutdown (4 messages)
- Transport "packet channel closed" shutdown messages (4 messages)
- Retry scheduling, discovery lookup initiation, other intermediate steps

Change default RUST_LOG from debug to info in systemd unit files.
2026-03-23 04:11:57 +00:00
Johnathan Corgan 6aff490251 Improve discovery protocol: bloom-guided tree routing with fallback
Replace discovery flooding with bloom-filter-guided tree routing:
lookups sent only to tree peers (parent + children) whose bloom
filter contains the target. If no tree peer matches, fall back to
non-tree peers with bloom matches before dropping the request. This
produces single-path forwarding through the spanning tree (90%
traffic reduction) while recovering from dead ends caused by stale
bloom filters, tree restructuring, or transit node failures.

Remove visited bloom filter from LookupRequest wire format (-257
bytes per request). Tree routing is inherently loop-free; request_id
dedup handles edge cases during tree restructuring. Add response-
forwarded flag to prevent response routing loops from convergent
request paths.

Add originator-side exponential backoff (30s base, 300s cap) after
lookup timeouts and bloom misses. Backoff resets on topology changes
(parent switch, new peer, first RTT, reconnection).

Add transit-side per-target rate limiting (2s minimum interval) for
forwarded lookups as defense-in-depth.

Add discovery retry within the timeout window (default: send at T=0,
retry at T=5s, fail at T=10s) to compensate for single-path fragility.
Lookups with zero eligible tree peers fail immediately.

Improve discovery logging: promote key events to info (initiation,
success, timeout with failure count). Add debug logging for dedup,
pending packet retry, backoff suppression, forward rate limiting,
and backoff reset.

New config: discovery.backoff_base_secs, backoff_max_secs,
forward_min_interval_secs, retry_interval_secs, max_attempts.
New stats: req_backoff_suppressed, req_forward_rate_limited,
req_bloom_miss, req_no_tree_peer, req_fallback_forwarded.
Removed: req_already_visited, visited bloom filter.
2026-03-22 20:02:00 +00:00
Johnathan Corgan 6c90cf6c02 Implement Tor transport with operator visibility
Add TorTransport in src/transport/tor/ supporting three operating modes:

Outbound (socks5 mode):
- Non-blocking SOCKS5 connect via tokio-socks with per-destination
  circuit isolation (IsolateSOCKSAuth)
- TorAddr enum for .onion and clearnet address types
- Connection pool with per-connection receive tasks, reuses TCP
  stream FMP framing
- connect_async()/connection_state_sync()/promote_connection() follow
  the same non-blocking polling pattern as TCP transport

Inbound (directory mode — recommended for production):
- Tor manages the onion service via HiddenServiceDir in torrc
- FIPS reads .onion address from hostname file at startup
- No control port needed — enables Tor Sandbox 1 (seccomp-bpf)
- Accept loop mirrors TCP pattern with DirectoryServiceConfig

Monitoring (control_port mode and optional in directory mode):
- Async control port client supporting TCP and Unix socket connections
  via Box<dyn AsyncRead/Write> trait objects
- AUTHENTICATE with cookie or password auth
- 8 GETINFO queries: bootstrap, circuits, traffic, liveness, version,
  dormant state, SOCKS listeners
- Background monitoring task polls every 10s, caches TorMonitoringInfo
  in Arc<RwLock> for synchronous query access
- Bootstrap milestone logging (25/50/75/100%), stall warning (>60s),
  network liveness transitions, dormant mode entry
- Directory mode optionally connects to control port when control_addr
  is configured (non-fatal on failure)

Operator visibility:
- show_transports query exposes tor_mode, onion_address, tor_monitoring
  (bootstrap, circuit_established, traffic, liveness, version, dormant)
- fipstop transport detail view: Tor mode, onion address, SOCKS5/control
  errors, connection stats, Tor daemon status section
- fipstop table view: tor(mode) label with truncated onion address hint

Security hardening:
- Per-destination circuit isolation via IsolateSOCKSAuth
- Unix socket default for control port (/run/tor/control)
- Reference torrc with HiddenServiceDir, VanguardsLiteEnabled,
  ConnectionPadding, DoS protections (PoW + intro rate limiting)

Config:
- TorConfig with socks5, control_port, and directory modes
- DirectoryServiceConfig: hostname_file, bind_addr
- control_addr, control_auth, cookie_path, connect_timeout,
  max_inbound_connections

Testing:
- 69 unit + integration tests with mock SOCKS5 and control servers
- Docker tests: socks5-outbound (clearnet via Tor) and directory-mode
  (HiddenServiceDir onion service)

Documentation:
- Transport layer design doc: Tor architecture, directory mode
- Configuration doc: Tor config tables and examples
2026-03-15 16:19:54 +00:00
Johnathan Corgan 1bfb58845a Implement non-blocking transport connect for connection-oriented transports
TCP (and future Tor) transports previously established connections
synchronously inside send(), blocking the node's RX event loop during
TCP handshake. This is particularly problematic for Tor where SOCKS5
circuit establishment can take 30-120 seconds.

Add a non-blocking connect path:
- ConnectionState enum in transport layer (None/Connecting/Connected/Failed)
- connect_async() on TcpTransport spawns background TCP connect task
- connection_state_sync() polls task completion, promotes to pool
- TransportHandle gains connect() and connection_state() dispatch methods
- Node tracks PendingConnect entries for connection-oriented transports
- initiate_connection() defers handshake for connection-oriented transports
- start_handshake() extracted as separate method for deferred invocation
- poll_pending_connects() in tick handler polls and completes handshakes
- Failed connects trigger retry via schedule_retry()

Connectionless transports (UDP, Ethernet) are unchanged — connect()
is a no-op and connection_state() always returns Connected.

The existing connect-on-send path in send_async() is preserved as
fallback for reconnection after connection drops.

811 tests pass (6 new), clippy clean.
2026-03-13 03:21:21 +00:00
Johnathan Corgan 2dc466f359 Add estimated mesh size from bloom filter cardinality
Compute network size estimate by summing bloom filter estimated entry
counts from the spanning tree parent (upward) and children (downward),
leveraging the tree's non-overlapping partition property. Uses the
standard formula n = -(m/k) * ln(1 - X/m) already in BloomFilter.

Surfaces the estimate in three places:
- show_status JSON: "estimated_mesh_size" field
- Periodic info log at MMP log interval (default 30s)
- fipstop Node dashboard State section as "mesh: ~N"
2026-03-09 00:10:31 +00:00
Johnathan Corgan 0bb6e70fb5 Add host-to-npub static mapping with DNS hostname resolution
Add a HostMap that resolves human-readable hostnames to npubs,
enabling `gateway.fips` instead of the full `npub1...xyz.fips`.
Two sources populate the map: peer `alias` fields from the YAML
config and an operator-maintained hosts file at /etc/fips/hosts.

The DNS responder auto-reloads the hosts file on each request by
checking the file modification time, so operators can update
mappings without restarting the daemon.

- New src/upper/hosts.rs: HostMap, HostMapReloader, hostname
  validation, hosts file parser with auto-reload on mtime change
- DNS resolver checks host map before falling back to direct npub
- Node uses host map for peer display names
- Default hosts file added to both .deb and tarball packaging
- 26 new tests (789 total)
2026-03-08 18:34:54 +00:00
Johnathan Corgan bf117df0ca Add periodic Noise rekey with fresh DH for forward secrecy (FMP + FSP)
Implement periodic full rekey at both protocol layers using fresh DH
key exchanges. Uses the existing K-bit flag (FLAG_KEY_EPOCH /
FSP_FLAG_K) to coordinate cutover between peers.

FMP layer (IK pattern):
- ActivePeer gains rekey state: pending/previous sessions, K-bit epoch
  tracking, drain window, dampening timer
- Handshake state stored on ActivePeer with msg1 sent on existing link
- Encrypted frame handler detects K-bit flips, promotes pending
  sessions, falls back to previous session during drain
- Handshake handlers distinguish rekey from new connections using
  addr_to_link lookup with identity-based fallback
- Free all session indices (current, rekey, pending, previous) on
  peer removal

FSP layer (XK pattern):
- SessionEntry gains parallel rekey fields with XK-specific state
  for the 3-message handshake
- Route availability check before FSP rekey initiation
- Encrypted session handler adds K-bit flip detection and dual-session
  decrypt fallback
- SessionSetup/Ack/Msg3 handlers extended for rekey paths

Defense-in-depth:
- Consecutive decryption failure detector (threshold=20) triggers
  forced peer removal instead of waiting for link-dead timeout
- Identity-based rekey detection as fallback when addr_to_link
  doesn't match (e.g., TCP ephemeral ports)

Configuration: RekeyConfig with enabled flag, after_secs (default 120),
and after_messages (default 65536) thresholds.

Logging: info for successful K-bit cutover completions, warn for
failures, debug for intermediate handshake steps, trace for routine
operations (resends, drain cleanup).

Rekey lifecycle:
1. Timer/counter fires -> initiator starts new handshake
2. Old session continues handling traffic during handshake
3. Handshake completes -> initiator cuts over, flips K-bit
4. Responder sees flipped K-bit -> promotes new session
5. Both keep old session for 10s drain window
6. After drain, old session discarded

Integration test: Docker-based multi-phase test exercising both FMP
and FSP rekey with aggressive timers (35s). Verifies connectivity
across all 20 directed pairs survives two consecutive rekey cycles.
Includes rekey topology, docker-compose profile, and CI matrix entry.

Increase ping test convergence wait from 3s to 5s for CI reliability.
2026-03-07 18:33:27 +00:00
Johnathan Corgan 56d39f223b Add ECN congestion signaling and transport congestion detection
Implement hop-by-hop ECN congestion signaling through the FMP layer,
transport-level congestion detection via kernel drop counters, and
chaos harness integration for end-to-end validation.

FMP/session ECN plumbing:

- Thread ce_flag parsed at link layer through dispatch_link_message,
  handle_session_datagram, handle_session_payload, and
  handle_encrypted_session_msg to session delivery
- Replace hardcoded false in session-layer record_recv() with actual
  ce_flag, activating ecn_ce_count tracking in session MMP

ECN congestion detection and CE relay:

- Add EcnConfig (node.ecn.*) with configurable loss_threshold (5%)
  and etx_threshold (3.0) for transit congestion detection
- Add send_encrypted_link_message_with_ce() that ORs FLAG_CE into FMP
  header flags; original method delegates with ce_flag=false
- Compute outgoing_ce = incoming_ce || local congestion on next-hop
  link, enabling hop-by-hop CE relay through transit nodes

IPv6 ECN-CE marking:

- Mark ECN-CE (0b11) in IPv6 Traffic Class on received DataPackets
  before TUN delivery when FMP CE flag is set
- Only marks ECN-capable packets (ECT(0)/ECT(1)); Not-ECT packets
  unchanged per RFC 3168

Transport congestion abstraction and UDP kernel drop detection:

- Add TransportCongestion struct to transport layer for transport-
  agnostic local congestion indicators
- Replace tokio::UdpSocket with AsyncFd<socket2::Socket> using
  libc::recvmsg() with ancillary data parsing
- Enable SO_RXQ_OVFL for kernel receive buffer drop counter on every
  packet, wiring up previously-stubbed UdpStats.kernel_drops
- Add TransportDropState for per-transport delta tracking with 1s
  tick sampling via sample_transport_congestion()
- Extend detect_congestion() with transport kernel drop check
  alongside MMP loss metrics

Congestion monitoring and control:

- Add CongestionStats (ce_forwarded, ce_received, congestion_detected,
  kernel_drop_events) to NodeStats with snapshot serialization
- Wire counters into forwarding path, session handler, and transport
  drop sampling with rate-limited warn logging (5s interval)
- Expose congestion data in show_routing control query and
  ecn_ce_count in show_mmp peer entries
- Add congestion counters to fipstop routing tab in two-column layout

Chaos harness integration:

- Add query_routing(), query_transports(), snapshot_all_congestion()
  to chaos control module
- Add congestion/kernel-drop log analysis in logs module
- Add congestion-stress scenario: 10-node tree, 1 Mbps bandwidth,
  5-10% netem loss, heavy iperf3 traffic
- Add IngressConfig for tc ingress policing with per-peer policer
  filters simulating upstream bandwidth bottlenecks
- Add iperf3 JSON result capture to traffic manager for throughput
  measurement across scenarios
- Add ECN A/B test scenarios (ecn-ab-on/off.yaml) with ingress
  policing and comparison script
- Enable TCP ECN negotiation (tcp_ecn=1 sysctl) in container
  entrypoint for end-to-end CE propagation

Tests:

- 10 ECN unit/integration tests: mark_ipv6_ecn_ce variants, CE relay
  chain (3-node propagation), EcnConfig serde roundtrip
- 3 transport drop congestion detection unit tests

Documentation:

- Update fips-mesh-layer.md: replace outdated CE Echo stub with full
  ECN Congestion Signaling section covering detection logic, CE relay,
  IPv6 marking, session tracking, and monitoring counters
- Update fips-configuration.md: add node.ecn.* parameter table and
  ecn block in complete reference YAML
- Update fips-transport-layer.md: add Congestion Reporting section
  with TransportCongestion struct, congestion() trait method, and
  per-transport status; document AsyncFd/recvmsg/SO_RXQ_OVFL in UDP
- Update chaos README: add congestion/ECN scenario docs, ingress
  traffic control, and iperf3 JSON capture sections
- Update README.md: add ECN to features list and "What works today";
  update transport and tooling entries
2026-03-05 17:05:57 +00:00
Johnathan Corgan 70e365b14d Fix PMTUD: per-destination path MTU check and ICMPv6 MTU field width
Two bugs prevented Path MTU Discovery from working across heterogeneous
links (e.g., ethernet→UDP boundary):

1. ICMPv6 Packet Too Big wrote the MTU as u16 into a 32-bit field
   (RFC 4443 §3.2), causing the kernel to read an inflated value.
   Fixed by changing build_packet_too_big() to use u32 and writing
   all 4 bytes.

2. handle_tun_outbound() only checked the local transport MTU, not
   the per-destination PathMtuState updated by MtuExceeded signals.
   Added a PathMtuState check after session lookup so subsequent
   oversized packets generate ICMPv6 PTB on TUN instead of being
   forwarded and dropped at the bottleneck hop.

Added integration test exercising the full PMTUD loop across a 3-node
chain with heterogeneous MTUs: oversized packet → forwarding failure →
MtuExceeded signal → PathMtuState update → ICMPv6 PTB on TUN.
2026-03-04 03:34:41 +00:00
Johnathan Corgan 77ac8c822e Add fipstop TUI monitoring tool with smoothed metrics and quality indices
fipstop: ratatui-based TUI for real-time monitoring of a running FIPS daemon.

Tabs and navigation:
- 8 navigable tabs: Node, Peers, Transports, Sessions, Tree, Filters,
  Performance, Routing
- Tab/BackTab navigation with group separators in tab bar
- Table views with selectable rows, detail drill-down panels, and scrollbars

Node tab:
- Runtime info: pid, exe path, uptime, control socket path, TUN adapter name
- Identity: npub, node_addr, ipv6 address
- State summary with peer/session/link/transport/connection counts
- TUN IPv6 traffic and forwarded transit traffic counters

Peers tab:
- Table with Name, Address, Conn, Depth, SRTT, Loss, LQI, Pkts Tx/Rx
- Detail panel: identity, connection info, transport cross-reference,
  tree/bloom state, link stats, MMP metrics with LQI

Sessions tab:
- Table with Name, Remote Addr, State, Role, SRTT, Loss, SQI, Path MTU,
  Last Activity
- Detail panel: identity, session info, traffic stats, MMP metrics with SQI

Transports tab:
- Hierarchical tree view: expandable transport parents with nested links
  (▼/▶ indicators, ├─/└─ tree chars, Space/Arrow to expand/collapse)
- Transport detail: type-specific stats (UDP/TCP/Ethernet)
- Link detail: peer cross-reference with MMP metrics and LQI

Performance tab:
- Link-layer MMP: SRTT, loss, ETX, LQI, goodput per peer
- Session-layer MMP: SRTT, loss, ETX, SQI, path MTU per session
- Trend indicators (rising/falling/stable) with context-aware coloring

Routing tab:
- Routing state: cache sizes, pending lookups, recent requests
- Coordinate cache: entries, fill ratio, TTL, expiry, avg age
- Statistics: forwarding, discovery request/response, error signal counters

Tree tab:
- Spanning tree position with 16 announce stats (inbound/outbound/cumulative)

Filters tab:
- Bloom filter announce stats, per-peer fill ratio and estimated node count

MMP metrics enhancements:
- Add etx_trend DualEwma for smoothed ETX tracking
- Add smoothed_loss() and smoothed_etx() accessors (long-term EWMA)
- LQI (Link Quality Index) = smoothed_etx * (1 + srtt_ms / 100)
- SQI (Session Quality Index) = same formula for session layer
- All loss/ETX displays prefer smoothed values with raw fallback

Control socket:
- Add smoothed_loss, smoothed_etx, lqi/sqi to show_peers, show_sessions,
  and show_mmp JSON responses
- Rename fips_address to ipv6_addr in show_status and show_peers
- Add tun_name and control_socket to show_status
- FHS-compliant 3-tier default path: $XDG_RUNTIME_DIR, /run/fips, /tmp

Node extensions:
- Add started_at/uptime() to Node
- Add tun_name() accessor

Docker sidecar updates:
- TCP transport support via FIPS_PEER_TRANSPORT env var
- Build scripts include fipstop binary
2026-03-01 16:33:33 +00:00
Johnathan Corgan 71a5c68fa9 Implement comprehensive node and transport statistics
Add 71 new counters (84 values) across three categories:

Node statistics (NodeStats, plain u64 — single handler context):
- Forwarding: 9 counters x (packets + bytes) = 18 values. Covers
  received, decode_error, ttl_exhausted, delivered, forwarded,
  drop_no_route, drop_mtu_exceeded, drop_send_error, originated.
- Discovery: 17 counters (packets only). Request path: received,
  decode_error, duplicate, already_visited, target_is_us, forwarded,
  ttl_exhausted, initiated, deduplicated. Response path: received,
  decode_error, forwarded, identity_miss, proof_failed, accepted,
  timed_out.
- Error signals: 3 counters — coords_required, path_broken,
  mtu_exceeded.
- Spanning tree: 16 counters. Inbound announce handling (received
  through accepted, parent switch, loop detection, ancestry change),
  outbound (sent, rate limited, send failed), cumulative events
  (parent switches/losses, flap dampening).
- Bloom filter: 10 counters. Inbound (received through accepted),
  outbound (sent, debounce suppressed, send failed).

Transport statistics (AtomicU64 + Arc — shared with spawned tasks):
- UDP (6 counters, 8 values): packets/bytes sent/recv, send_errors,
  recv_errors, mtu_exceeded, kernel_drops (stub for SO_MEMINFO).
- TCP (10 counters, 12 values): packets/bytes sent/recv, send_errors,
  recv_errors, mtu_exceeded, plus connection lifecycle counters
  (established, accepted, rejected, timeouts, refused).

Control socket integration:
- show_routing: forwarding, discovery, error signal stats
- show_tree: spanning tree stats + per-peer bloom metrics
  (estimated_count, set_bits, fill_ratio) and coordinate paths
- show_bloom: bloom filter stats + per-peer snapshots
- show_transports: per-transport stats snapshots

Also refactor UDP transport from flat files (udp.rs + udp_stats.rs)
into directory module (udp/mod.rs + udp/stats.rs) matching TCP
structure, and fix pre-existing clippy warnings in tree/tests.rs.
2026-02-28 18:23:04 +00:00
Johnathan Corgan ec64a0dce1 Add TCP transport implementation and test harness support
Implement TCP transport for FIPS enabling firewall traversal and serving
as the foundation for future Tor transport. This is the first
connection-oriented transport in the system.

Key design decisions:
- FMP header-based framing: reuses existing 4-byte FMP common prefix for
  packet boundary recovery with zero framing overhead
- Session survives TCP reconnection: Noise/MMP/FSP state bound to npub,
  not TCP connection; MMP liveness is sole authority for peer death
- Connect-on-send: fresh connection on first send, transparent reconnect
- close_connection() trait method for cross-connection deduplication cleanup

New transport files:
- src/transport/tcp/mod.rs: TcpTransport, connection pool, accept loop
- src/transport/tcp/stream.rs: FMP-aware stream reader (shared with Tor)

Modified: transport trait (close_connection), TcpConfig, TransportHandle
match arms, create_transports(), initiate_connection() for connection-
oriented links, cross-connection tie-breaker cleanup, design docs.

Tree announce loop and TCP stability fixes:
- Preserve tree announce rate-limit state across reconnection: carry
  forward last_tree_announce_sent_ms when a peer reconnects so the
  rate-limit window isn't reset to zero
- Drop oversize TCP packets at sender: pre-send MTU check returns
  MtuExceeded instead of writing to the stream, preventing receiver-side
  connection teardown and reset-reconnect cycles

Chaos harness:
- TCP transport support: tcp_edges/has_tcp/tcp_peers in SimTopology,
  transport-aware config_gen with per-edge transport type, TCP port 443,
  pure-TCP node support
- Include all non-Ethernet edges in directed_outbound()
- Fix netem/links log messages to say "IP-based" instead of "UDP"
- Add tcp-chain, tcp-only, and tcp-mesh scenario files

Static harness:
- Transport-aware config generation (get_default_transport, transport_port)
- TCP transport injection via Python post-processing
- Add tcp-chain topology and docker-compose profile
2026-02-27 00:41:37 +00:00
Johnathan Corgan d29da442ac Add Ethernet transport with beacon discovery
Implement raw Ethernet transport using AF_PACKET SOCK_DGRAM on Linux
with EtherType 0x88B5 (IEEE experimental range) and 1-byte frame type
prefix (0x00=data, 0x01=beacon).

Transport implementation:
- EthernetConfig with interface, ethertype, MTU, buffer sizes, and
  four independent discovery knobs (discovery, announce, auto_connect,
  accept_connections)
- PacketSocket/AsyncPacketSocket wrappers with ioctl helpers for
  interface index, MAC address, and MTU queries
- EthernetTransport with Transport trait impl, async start/stop/send,
  receive loop dispatching data frames and discovery beacons
- Discovery beacons (34 bytes: type + version + x-only pubkey) with
  DiscoveryBuffer for peer accumulation and dedup
- Atomic statistics counters (frames, bytes, errors, beacons)
- Platform-gated with #[cfg(target_os = "linux")]

Transport-layer discovery integration:
- Promote auto_connect() and accept_connections() to Transport trait
  with default implementations and TransportHandle dispatch
- Extract initiate_connection() so both static peer config and
  discovery auto-connect share the same handshake initiation path
- Add poll_transport_discovery() to the tick handler to drain
  discovery buffers and auto-connect to discovered peers
- Enforce accept_connections() in handle_msg1() — transports with
  accept_connections=false silently drop inbound handshakes

Node integration:
- create_transports() handles Ethernet named instances
- resolve_ethernet_addr() parses "interface/mac" address format
- transport_mtu() generalized for multi-transport operation

Test harness:
- VethPair RAII struct for veth pair lifecycle management
- Three #[ignore] integration tests requiring root/CAP_NET_RAW:
  two-node handshake, data exchange, mixed transport coexistence
- Chaos harness: transport-aware topology model, VethManager for
  veth pairs between Docker containers, Ethernet-aware config gen,
  netem split (HTB+u32 for UDP, root netem for veth), transport-aware
  link flaps and node churn with veth re-setup
- Container entrypoint waits for configured Ethernet interfaces
  before starting FIPS (handles veth creation timing)
- New scenarios: ethernet-only (4-node ring), ethernet-mesh (6-node
  mixed UDP+Ethernet with netem and link flaps)

Documentation:
- fips-transport-layer.md: Ethernet section, beacon discovery, WiFi
  compatibility, updated discovery state, trait surface additions,
  implementation status table
- fips-configuration.md: Ethernet parameter table, named instances,
  peer address format, mixed UDP+Ethernet example, complete reference
- fips-wire-formats.md: Ethernet frame type prefix note
2026-02-26 00:03:14 +00:00
Johnathan Corgan 58664c7c77 Update dependencies: rand 0.10, rtnetlink 0.20, tun 0.8, and others
Bump rand (0.8→0.10), rtnetlink (0.14→0.20), tun (0.7→0.8),
simple-dns (0.9→0.11), socket2 (0.5→0.6), and criterion (0.5→0.8).

Migrate all rand call sites: thread_rng()→rng(), gen()→random(),
gen_range()→random_range(), RngCore→Rng trait. Work around secp256k1
0.30 requiring rand 0.8 by generating random bytes directly and
constructing SecretKey from slice.

Migrate rtnetlink to builder-based API: LinkSetRequest replaced with
LinkUnspec builder + change(), RouteAddRequest replaced with
RouteMessageBuilder.

Remove bloom benchmark (criterion 0.8 incompatible with old harness
config).
2026-02-24 18:02:06 +00:00
Johnathan Corgan 94c0e19951 Add flap dampening to parent selection
Track parent switch frequency in a sliding window. When switches exceed
a configurable threshold (default 4 in 60s), impose an extended hold-down
period (default 120s) that prevents non-mandatory parent changes.

Mandatory switches (parent loss, root change, shouldn't-be-root) bypass
dampening. The flap counter resets when the window expires naturally.

Implements TASK-2026-0030 / IDEA-0013.
2026-02-23 20:00:58 +00:00
Johnathan Corgan e3b5bd0bcd Fix identity cache miss during lookup response verification
Guard discovery triggers in handle_path_broken() and
handle_coords_required() with has_cached_identity() check. When the
XK responder receives an error signal before msg3 completes, the
initiator's identity is unknown, making LookupResponse proof
verification impossible. Skip discovery in this case — the handshake
retry mechanism handles recovery.

Downgrade the identity_cache miss log from ERROR to WARN since it's a
known race condition, not a bug.
2026-02-23 18:44:27 +00:00
Johnathan Corgan 0d93a19e07 Implement cost-based parent selection with periodic re-evaluation
Cost-based parent selection:
- Replace depth-only parent selection with effective_depth = depth + link_cost
- link_cost computed from locally measured MMP metrics: etx * (1.0 + srtt_ms / 100.0)
- Prevents bottleneck subtrees in heterogeneous networks where a LoRa link
  at depth 1 would otherwise always beat fiber at depth 2
- Configurable hysteresis (default 0.2) prevents marginal parent switches
- Configurable hold-down timer (default 30s) suppresses re-evaluation
  after parent switch
- Mandatory switches (parent lost, root change) bypass both safeguards
- Link costs passed as HashMap parameter to keep TreeState pure

Periodic re-evaluation:
- evaluate_parent() was only called on TreeAnnounce receipt or parent loss;
  after tree stabilization, link degradation went undetected
- Added timer-based re-evaluation (reeval_interval_secs, default 60s) that
  calls evaluate_parent() from the tick handler with current MMP link costs
- Respects existing hold-down and hysteresis safeguards
- Short-circuits when disabled or <2 peers

Design documentation:
- Update 7 design docs to reflect cost-based parent selection
- Replace depth-only algorithm descriptions with effective_depth model
- Replace rejected cumulative path cost spec with local-only design rationale
- Rewrite Example 2 (heterogeneous links) for local-only cost model
- Update config docs: parent_switch_threshold replaced by parent_hysteresis,
  hold_down_secs, reeval_interval_secs

Chaos simulation enhancements:
- fips_overrides with deep merge for per-scenario FIPS config customization
- Explicit topology algorithm for deterministic test graphs
- Control socket querying via fipsctl for tree/MMP snapshot collection
- Edge existence validation in netem manager
- Per-link netem policy overrides
- 9 new chaos scenarios covering cost avoidance, depth-vs-cost tradeoffs,
  stability, mixed topologies, periodic re-evaluation, and bottleneck parent

12 new unit tests, 667 total passing, clippy clean.
2026-02-23 17:15:20 +00:00
Johnathan Corgan 717be3d960 Restrict bloom filter propagation to tree edges, update design docs
Gate peer_inbound_filters() to only collect from tree peers (parent
and children), so outgoing filter computation merges only tree-sourced
information. All peers still receive FilterAnnounce messages and store
filters locally for routing queries — the restriction is only on what
gets merged into outgoing filters.

This prevents bloom filter saturation where mesh shortcuts cause every
node's filter to converge toward the full network. With tree-only
merge, filters contain subtree (from children) + complement (from
parent) + single-hop mesh views.

Implementation:
- Add is_tree_peer() helper to determine tree parent/child relationship
- Gate peer_inbound_filters() to tree peers only (single control point)
- Trigger bloom filter exchange on tree relationship changes
- Add est_entries, set_bits, fill ratio, and tree_peer fields to
  FilterAnnounce send/receive debug logs
- Add test_bloom_filter_split_horizon test verifying directional
  asymmetry: upward filters contain only the child's subtree, downward
  filters contain only the complement
- Add print_filter_cardinality diagnostic helper for test inspection

Design docs:
- fips-bloom-filters.md: Add directional asymmetry and mesh peer filter
  subsections, update per-peer filter model, saturation mitigation,
  implementation status table
- fips-mesh-operation.md: Update filter propagation description, add
  directional asymmetry, tree relationship change trigger
- fips-intro.md: Rewrite bloom propagation paragraph for tree-only merge
2026-02-23 14:00:00 +00:00
Johnathan Corgan 20cf6932cd Implement reactive MtuExceeded error signal (0x22)
Add a new session-layer error signal that transit routers send back to
the source when a forwarded packet exceeds the next-hop transport MTU.
This complements the existing proactive path MTU discovery (min'd at
each hop) by providing immediate feedback when oversized packets are
dropped, closing the transient window before the proactive mechanism
converges.

Wire format: 36-byte payload (msg_type + flags + dest_addr + reporter +
mtu) with FSP phase=0x0 and U flag set, matching the existing
CoordsRequired/PathBroken pattern.

Changes:
- Add SessionMessageType::MtuExceeded (0x22) and MtuExceeded struct with
  encode/decode methods to protocol/session.rs
- Add NodeError::MtuExceeded variant to propagate structured MTU info
  from TransportError through send_encrypted_link_message()
- Catch MtuExceeded in the forwarding path and send error signal back to
  the datagram source via send_mtu_exceeded_error(), rate-limited by the
  existing routing_error_rate_limiter
- Handle incoming MtuExceeded at the source by calling
  PathMtuState::apply_notification() for immediate MTU decrease
- Add unit tests for encode/decode roundtrip, boundary MTU values, and
  too-short payload rejection
2026-02-22 21:37:31 +00:00
Johnathan Corgan 0a6d433d32 Add Unix domain control socket for runtime observability
Add a Unix domain socket interface for querying node state at runtime.
A spawned tokio task accepts connections and communicates with the main
event loop via mpsc/oneshot channels, keeping all Node access
single-threaded.

Includes:
- src/control/ module with socket lifecycle, JSON protocol, and 11
  query handlers (status, peers, links, tree, sessions, bloom, mmp,
  cache, connections, transports, routing)
- Separate fipsctl binary for CLI queries (fipsctl show <command>)
- ControlConfig in node configuration (enabled, socket_path)
- Integration into the main select! event loop
2026-02-22 20:53:00 +00:00
Johnathan Corgan f920526ece Add epoch-based peer restart detection to Noise IK handshake
Each node generates a random 8-byte startup epoch, encrypted inside
both Noise IK handshake messages (msg1 and msg2). When a peer's msg1
arrives with a different epoch than the stored value, the node tears
down the stale session and processes the msg1 as a new connection,
enabling near-instant restart detection instead of the 30-second
dead timeout.

Wire format impact:
- msg1: 82 -> 106 bytes (added 24-byte encrypted epoch after ss DH)
- msg2: 33 -> 57 bytes (added 24-byte encrypted epoch after se DH)
- Wire msg1: 90 -> 114 bytes, wire msg2: 45 -> 69 bytes
2026-02-22 20:50:50 +00:00